Lichen Spotlight – Vulpicida pinastri

The Powdered Sunshine Lichen or Vulpicida pinastri is certainly one of the most striking of Colorado lichens. For those of us who like to identify lichen to species it also happens to be highly distinctive!

Vulpicida pinastri – Gregory Canyon, Boulder CO

This species is quite common once you know where to look for it. It likes cool wetter areas in the higher areas of the foothills up to timberline. It is a corticolous lichen, fancy scientist speak for growing on trees of bark. The species has a particular fondness for stumps, especially where humans have cut down a tree. Like other species that prefer exposed wood and not bark, it also grows on other human-made substrates like fences.

It can be rather immediately identified by its erect foliose structure, the intense yellow marginal soredia that look like a crust on the outer edges of the lichen, and a blue-green thallus. This species is almost always sterile, meaning the lichen only reproduces asexually by the dispersal of tiny particles of those beautiful yellow soredia.

Vulpicida pinastri on an old stump, a common substrateGregory Canyon, Boulder CO. Click to enlarge.

I tried to find more about the species’ natural history, and like many lichens there is not much out there. It is a Holarctic species distributed in northern hemisphere in both North America and Eurasia. It can be found in boreal forests and at higher elevations in mountains further south. That’s us in Colorado! One study1 used this species to show that some lichen substances are indeed toxic and are a possible way to limit anything from eating them. Another presentation2 made the bold claim that chemicals produced could have potential in the treatment of Alzheimer’s! At any rate surely there is more to learn about this lichen, but for now head up into the mountains and try and spend some time with your new acquaintance Vulpicida pinastri.

1 Pöykkö, H., Hyvärinen, M., & Bačkor, M. (2005). Removal of lichen secondary metabolites affects food choice and survival of lichenivorous moth larvae. Ecology, 86(10), 2623–2632.

2 Ureña Vacas, I. M., González Burgos, E., & Gómez-Serranillos, M. P. (2019). Antioxidant capacity and cholinesterase inhibitory activity of vulpicida pinastri lichen and its chemical composition. Proceedings of 5th International Electronic Conference on Medicinal Chemistry.

Umbilicaria, or Rock Tripe

Umbame1882Umbilicaria americana, FROSTED ROCK TRIPE
This species and its relatives are known as “rock tripe” and said to be edible, though perhaps only in dire situations. For example, the related species Umbilicaria mammulata reportedly fed George Washington and his starving troops during the harsh winter of 1777 at Valley Forge. A distinctive and abundant lichen on moist, vertical cliff faces in the Front Range, it lacks apothecia and has a sooty black underside covered with rhizines, creating a velvety appearance.

umbil2346smThalli are leathery (and green!) when wet, and are “umbilicate” (attached only at one central point); they can be 15 cm across. Largest and most notable of our umbilicate species, this often grows in huge colonies.

Another large species of Umbilicaria, this brownish one with abundant black apothecia and a more wrinkled upper cortex. Perhaps U. hyperborea.

Fun fact: Some species of Umbilicaria have intriguing black “gyrose” apothecia with concentric fissures. This species, however, is rarely seen with apothecia.

Don’t be fooled: Umbilicaria vellea is similar, but usually smaller and generally found at higher elevations or latitudes. Details of the rhizines distinguish the two.

A monotypic colony of Umbilicaria on metamorphic rock cliffs in Bear Creek Canyon, Jefferson Co., Colorado.

A monotypic colony of Umbilicaria on metamorphic rock cliffs in Bear Creek Canyon, Jefferson Co., Colorado.

Peltigera leucophlebia

Or is it Peltigera aphthosa? Only by peeking underneath can you be sure! This post was published as a lichen profile in the Winter 2013 issue of Aquilegia, newsletter of the Colorado Native Plant Society (Vol 37, No. 6). Back issues are available online at the CoNPS website..

Peltigera leucophlebia, Peltigera aphthosa

Photo by Rick Brune.

Photo by Rick Brune.

Broad, ruffled lobes would place the abundant “pelt” lichens among the most noticeable of our montane lichens, were it not for their usual cryptic brown and gray coloring. Fortunately three of our 15 species stand out, at least when wet, thanks to the chlorophytes that are their primary photobionts. Peltigera aphthosa and Peltigera leucophlebia (clear veins) are large lichens with bright green coloring that helps us spot them when the forest floor is moist. The 2-4 cm wide lobes radiate to form a thallus 30 cm or more across.

To distinguish these two species, you’ll probably have to take a peek at the underside. P. leucophlebia, as its name implies, has distinct veins that change from light colored near the margin to black toward the center. Carefully loosen the lichen from the soil or mosses to check for this. In P. aphthosa, the veins tend to be broad and undefined. The uplifted lobes bearing brownish apothecia have, in P. aphthosa, green cortex on the underside of these reproductive structures, but in P. leucophlebia, the cortex is absent or present only as green specks on the white background.

Fun fact: Round dark structures on the upper surface, called cephalodia, contain cyanobacteria, giving these lichens claim to a three-kingdom symbiosis.

Don’t be fooled: Species of Sticta look like Peltigera and are in the same family, but the underside is black with white spots instead of the characteristic veins. Our third green Peltigera, P. venosa, is smaller (less than 2 cm diameter) and each fan-shaped thallus consists of a single lobe, usually with black marginal apothecia.

Scans of upper (left) and lower (right) surfaces of Peltigera leucophlebia, by Richard Brune.

Scans of upper (left) and lower (right) surfaces of Peltigera leucophlebia, by Richard Brune.